top of page

Hot Heart, a project for an archipelago of floating, energy-generating islands.

If there is one place in the world that is serious about fighting global warming and aspiring to be carbon dioxide (CO2) free by 2023, it is the Helsinki Energy Challenge in Finland.



Hot heart

In 2021, the grand prize winner of the Helsinki Energy Challenge was the Hot Heart project designed by Italian architecture firm Carlo RattiAssociati.


Located just off the coast of Helsinki, Finland, the islands have been designed to convert the green energy produced into hot water, stored in giant bubbles. These bubbles can also be used to heat cities in winter.


Photo credit: Carlo RATTI ASSOCIATI

Photo credit: Carlo RATTI ASSOCIATI

Even crazier, four of the ten mega tanks will house XXL plant life (artificial tropical forests and various ecosystems from around the world). The programme on board these giant bubbles will include family rides through tropical forests, saunas and rest areas.


Photo credit: Carlo RATTI ASSOCIATI

Photo credit: Carlo RATTI ASSOCIATI




"Renewable energy production is becoming cheaper, but storage is still extremely expensive. Our idea is to use giant 'thermal batteries' to store energy when prices are low or even negative, and to extract it when the district heating system requires it when demand is high. This model would also be applicable to many coastal cities with similar climates,"


"In addition, Hot Heart offers a unique experience, bringing together the natural and man-made worlds. It is inspired by the Finnish concept of Jokamiehen Oikeudet, which could be translated as 'every person's right': the right to reflect and relax while peacefully enjoying nature."

explains Carlo Ratti, founding partner of Carlo RattiAssociati.






These floating islands will soon be used to air-condition cities.

Scheduled for 2028, it is hoped to see these eco-domes all around Europe's coastal cities.





bottom of page